intrusive:below ground
extrusive:at the surface
Extrusive is a form of igneous rock - it's what you get when the magma is extruded or squeezed out onto the surface in the form of lava.
"intrusive" means forced into something, "extrusive" means forced out onto the surface. The igneous magma reaching the surface is therefore extrusive , producing extrusive igneous rocks, and all the rest of the magma is intrusive, producing intrusive igneous rocks.
The crystal growth of intrusive igneous is substantially more so than extrusive igneous. Magma cools quicker on the earth's surface, extrusive igneous formed, as opposed to below the crust, intrusive. Therefore the longer it takes to cool the magma, the more the crystal growth.
Volcanic glass is an extrusive igneous rock. It forms when molten lava cools quickly on the Earth's surface, preventing the formation of crystals.
Intrusive igneous rocks cool beneath the crustal surface. Extrusive cool above the surface - pillow lavas cool below the sea but above the crust.
Igneous rocks are described as intrusive or extrusive based on formation. Intrusive rocks forms underneath the earth surface, while extrusive rocks forms on the surface of earth.
The terms intrusive and extrusive apply to the formation of igneous rocks. Silica is a chemical component of a wide variety of minerals found in many types of igneous, metamorphic, and sedimentary rock. All igneous rocks, both intrusive and extrusive, contain silica.
instrusive is inside the valcano and exstrusive comes onto earth's crust
instrusive is inside the valcano and exstrusive comes onto earth's crust
Extrusive igneous rocks have smaller crystals due to rapid cooling on the Earth's surface, while intrusive igneous rocks have larger crystals due to slower cooling beneath the Earth's surface. This difference in crystal size can help distinguish between the two types of rocks.
Basalt is the most common extrusive igneous rock.
The crystals within don't have as much time to grow when igneous rock is cooled more quickly as in extrusive igneous formation.